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Fig. 2: Triangle marking exam Marking similar components with a continuous triangle (as shown here for the stiles and rails of a door frame) is a quick way to distinguish the face side and location of parts. This marking system allows you to determine, at a glance, which edge or end of a part should be mortised, tenoned or grooved. Door rails I made one from V2-in.-thick birch plywood, with four %-in.-Iong #5 screws in the bottom side to level it exactly to the saw table. To ple, requires a 'l4-in. and a Ys-in. spacer between the two blades. Using two blades at once requires a new table insert for the saw. install the table insert, retract the blades completely below the surface of the table, and then place the plywood in the opening and level it by adjusting the four screws. Now place the rip fence over the edge of the insert to hold it down. Turn on the saw, and raise the blades to maximum tenon-cutting height. Auxil獴ᐏ㭨၀ fence for en dgra獴ᐏ cuts You can buy tablesaw tenoning jigs for cutting stock held on end, but I prefer a shop-built auxiliary fence, as shown in the photo on p. 72, because the workpiece doesn't have to be clamped in place during each pass over the saw. As you can see in the photo, the fence has a slot running parallel to the saw table to accept a standard miter gauge. With the blade fully raised, the fence must be tall enough so that the lower edge of the miter gauge clears the blade by a couple of inches and still has its base fully supported by the fence. The fence pictured here is 13 in. high, with the slot 7 in. from the bottom. Because it is absolutely essential that the cheeks of the tenon are parallel to the face of the stock, I made my fence adjustable for squareness with the table. This adjustment is simply a brace on the back of the fence set at just under 90°. The brace shown in the photo below has a kerf partially across it, making it flexible enough to be moved by an adjustment screw until it's square to the table. This adjustment should be checked every time the fence is used. Once the fence is screwed to the rip fence and squared to the Assembled door frame table, place the miter gauge in the slot and hold it there. Next, screw a piece of scrap to the miter gauge to serve as a backup board to minimize tearout. The backup board should be long enough to seat firmly against the miter gauge and sit solidly on the saw table. Any wood will do as long as it's flat and accurately dressed. I hold the gauge in the slot as I push it and the workpiece past the blade. After setting up the auxiliary fence and miter gauge, you are saw table by means of a spring· like block screwed to the fence's brace. A kerf partially across the block provides enough flexibility to tip the fence by driving a single screw in or out. 74 Fine Woodworking The auxiliary fence can be adjusted so it's exactly 90° to the ready to adjust the blade spacing. This only needs to be done once for each set of blades, spacers and bits, although you should recheck the system each time the sawblades or the router bit used for mortising is sharpened. Trial and error is the most efficient method here. Cut a few mortises in several pieces of scrapwood; then insert spacers and shims between the two blades until they'll cut a tenon to match the mortises. In my setup for %-in.-thick tenons, this would mean installing the two sawblades with a V4-in. and VB-in. spacer in between (because the teeth have no set, spacing the blade bodies % in. apart makes the teeth % in. apart). With the blades set to produce the desired tenon length, cut the cheeks on a piece of scrap. For convenience, this scrap should not be wider than the desired tenon. At this point, I usually just bandsaw the shoulders to remove the waste because shoulder alignment is not important for a test piece. Then I check the tenon thickness in the mortise. You'll probably have to adjust blade spacing with shims to get a good fit. Keep playing with the setup until the tenon fits smoothly and snugly; you shouldn't have to hammer it in place. (Remember that a fit that is too tight will wipe away all the glue during assembly and leave you with a wonderfully machined joint that doesn't last.) Once you have found the right combination of spacers and shims, mark them clearly in case you want to cut the same tenons in the future. Once everything is aligned and tested, you are ready to put this whole process to work. All of your stock should be marked for correct joinery orientation. The triangle marking system shown in figure 2 above does this quickly and clearly (for more on triangle